50 -
Mutalisk
[15x]
at 08:20
(When spire finishes, just get as many as you can, and keep producing LINGS and MUTAS and HARASS and CRUSH YOUR OPPONENT!)

Description

This build opens with an economic 2 base Muta opener, and uses a 7:20 Overlord scout coupled with the initial Mutalisk harass to determine whether your Terran opponent is using a Bio-based composition, or a Mech-based composition.

All the supply and time listed is tentative, meaning you should always defend against what your opponent is doing, and make sure you are stable in economic standards and production. This is an all-around build that can harass your enemy and is very stable, but in case of cheese, transition into Roach/Hydra/Baneling defense.